Wi-Fi vs Ethernet: which devices should be wired?

Wi-Fi has improved so much that people ask whether cabling still makes sense. It does: cable doesn’t compete with Wi-Fi — it makes Wi-Fi work better. Every fixed device you move to a cable leaves more wireless capacity for the devices that move.

Key differences

Aspect	Ethernet cable	Wi-Fi
Stability	Constant	Varies with distance, obstacles and load
Latency	Very low and steady	Higher and variable
Real-world speed	The full link, not shared	Shared among devices on the same access point
Interference	Practically none	Neighbouring networks, appliances, walls
Mobility	No	Yes
Power	Possible via PoE	No

What to wire

• Wi-Fi access points: the foundation of good coverage (see improving Wi-Fi in a large house).
• TVs and streaming boxes: high-resolution streaming loves a steady connection.
• Consoles and desktops: lower latency for gaming and video calls.
• NAS and backups: large volumes of data.
• Security cameras: with PoE, one cable carries data and power.
• Smart-home gateways and servers: KNX/IP interfaces, controllers, touch panels.
• Home-office desk: stable video calls and reliable VPN (see our remote work service).

What can stay on Wi-Fi

• Phones, tablets and laptops.
• Smart speakers and low-power smart-home devices.
• Devices in places cable can’t reach, with light usage.

Which cable to choose

• Category 6: a solid baseline for homes and offices — 1 Gbps up to 100 m, higher speeds over shorter runs.
• Category 6A: 10 Gbps up to 100 m — recommended for offices, backbone links and future headroom.
• Fibre optic: between floors or buildings, over long distances or where there’s interference (see structured cabling and fibre).

Any copper link is limited to about 100 metres. Beyond that you need intermediate switches or fibre.

Planning your data points

1. One central point (a comms cabinet or rack) where the ISP fibre, router and switch live.
2. Star topology: every outlet runs straight back to the central point, with no joins.
3. Ceiling points for planned Wi-Fi access points.
4. Spare capacity: leave room in conduits and a few extra outlets.
5. Labelling and testing: every outlet identified and certified.

In new buildings in Spain, the telecom infrastructure regulation (RD 346/2011) already requires an in-home network; the point is to size it for real use, not just the legal minimum. More in what architects and builders should plan.

Worked example: a four-bedroom home

Room	On cable	On Wi-Fi
Living room	TV, streamer, console, ceiling access point	Phones, smart speaker
Home office	Desktop, printer, docking station	Laptop when it moves
Bedrooms	One outlet each for a future TV or study desk	Phones and tablets
Comms cabinet	Router, switch, NAS, camera recorder, automation gateway	—
Outdoors	PoE cameras and an outdoor access point	Garden devices

With this split, Wi-Fi only serves what moves, and stays responsive even with lots of connected devices.

Common mistakes

• Putting every outlet in the living room and none where access points will go.
• Flat or low-quality cables that don’t meet their stated category.
• Joining cables inside back boxes.
• Running data cables in the same conduits as mains power.
• Not documenting where each cable goes.

Conclusion

The rule is simple: fixed devices on cable, mobile devices on Wi-Fi. With a well-planned wired network, Wi-Fi performs better, cameras and automation are stable and the home or office is ready for years. If you’re building or renovating, now is the time to plan outlets and conduits.

Domolife designs and installs structured cabling and Wi-Fi networks. Tell us about your project.